Heating device



sept. 3, 1929. l

O. J. FAY ET ALA HEATING DEyICE Filed Dec, 23, 1927 Patented v Sept. 3,1929.

UNITED STATES PATENT OFFICE.

OWEN JAMES FAY, F CHICAGO, HARRY T EMERSON PUGH, OF CHICAGO, ILLINOISOBIAS HEIMBERGER, 0F RIVERSIDE, AND ASSIGNORS T0 WESTERN ELECTRIC COM-IEANY,v INCORPORATED, OF NEW YORK, N. Y., .A CORPORATION OF NEW YORK.

HEATING DEVICE.

Application led December 23, 1927. Serial No. 242,046.

This invention relates to a heating device,

and more particularly to an electrically heated soldering iron.

The object of this invention is to provide an improved heating device ofsimple and practical construction which permits of a quick and easyassembly or convenient replacement of parts thereof. y

A preferred embodiment of the invention consists of an electricallyheated soldering iron, wherein a unitary replaceable double helixheating element insulated from and surrounding a solid heat conductingcore has reinforced wire terminals passing through slots in a cap andthrough separated longitudinal passageways in a stem insulator. The endsof the heating element are attached to connectors on opposite sides ofan insulating strip which engages a slot in the end of the steminsulator and is fastened in a handle by a slotted sleeve. 'Theconnectors extend through and terminate in the end of the handle and areengaged by a quickly detachable electrical contact socket which isenclosed by a retaining cap threaded on the end of the handle.

Other objects will appear more clearly from the following one embodimentof the invention, taken in connection with the accompanying drawings, inwhich Fig. 1 is a longitudinal elevation, partly in section, of asoldering iron, embodying the features of the invention;

Fig. 2 is a sectional view taken on lines 24-2 of Fig. 1;

Fig. 3 is an enlarged cross-sectional view taken on lines 3 3 of Fig. 2;

v Fig. 4 is an enlarged cross-sectional yview taken on lines 4 4 of Fig.2;

Fig. 5 is an enlarged fragmentary detail View of the resistor windingshowing the reinforced wire terminals thereof, and

Fig. 6 isan enlarged fragmentary perspective view disclosing a means forlocking the metal shell encasing the heating unit to the stem assemblyof the handle.

Referring now to the drawings wherein like reference numerals refer tosimilar parts throughout the several views, the numeral 10 designates aheating element of any suitable high resistance electrical conductingmaterial formed into a helix with a straight lead 11 on each end. Thehelically formed redetailed description of sistance wire 10 is wound ina loop over a helically grooved cylinder 1'2 constructed of any suitablerefractory insulating material, starting around a protruding post 13 atthe forward end of the refractory cylinder 12 as illustrated in Fig. 1.The helices are so spaced that they are out of contact with each other,thus reventing a short circuit which would ren er part of the resistorilieifective to generate heat. In order to strengthen the leads and toincrease their conductivity thereby minimizing the generation of heat inthe leadsythree eXtra wires are inserted a short distance inside thehelix and are twisted with a lead to form a reinforced strandedterminal. This feature assists in keeping the handle from becoming hotsince the reinforced leads having a lowered resistance do not generateany appreciable amount of heat. The leads 11 of the resistor 10 arethreaded through apertures 111-14 in protruding portions 15diametrically opposite each other atthe upper end of the insulatingcylinder 12 and then through holes 16 to the interior of the insulatingcylinder l2. From the inside of the insulating cylinder 12 the leads 11are passed through slots 20 into a substantially rectangular shapeddepression 25 in an insulating cap 21 and from there through separatedlongitudinal passageways 22 in an insulating stein of refractorymaterial 23 having a substantially rectangular end 24: which fits intothe substantially rectangular depression 25 in `the cap 21 and is thusinterlocked with the cap. The other end of the stem insulator 23 isprovided with a rectangular slot 30 into which an insulating strip 31fits carrying a connector bar 32 on either side and having `screws 33-33by means of which the leads 11 of the resistor 10 are secured thereto.The connectors are crim ed over the edges of the strip 31 and in adition are secured by the screws 33 and an insulating band 34, and theyextend out of and beyond the end of a woodenhandle 35 so that electricalsupply terminals 36 in a socket 37 can lbe engaged with the connectors32.` The socket terminals may be connected through a cord 38 to asuitable source of electrical energy.

A detachable retaining cap 40, which may be of any suitable metal,ythreaded on the handle 35 is adapted to rigidly maintain the electricalsupply socket 37 in contacting pothe clamp 42 las it bears against thewasher 41 held in place by the cap 40, thereby pre-- venting the cordfrom being torn from the terminals 36 in the socket 37.

The lower end of the handle 35 is tfireaded into a metallic collar -45which in turn is threaded onto a member 46 forcibly driven on a metallictube 47 surrounding the stem insulator 23. A. flanged sleeve 48 having aslot extending through the flange and longitudinally thereof, fits overthe metallic tube 47 and the insulating strip 31 which Ahas a widenedportion 39 (Fig. 1) extending through a slot in the tube 47 and the slotin the sleeve 48. The flange ofthe sleeve 48 bears against the end ofthe handle under the collar 45 and serves to rigidly interlock thesemembers and prevent an accidental withdrawal of the insulatin stripthrough the opening in the end of t e handle. At the lower end of themetallic tube 47, a thimble 50 is forcibly driven thereon and has athreaded end on which is screwed-a metal shell 51 encasing the heatingelement 10.and separated therefrom /by a mica cylinder 52. f A thinmeta-l washer 53 is placed between the shoulder of the threaded part ofthe thimble 50 and the metal shell 51 screwed thereon. The washer isadapted to interlock the thimble and shell when the washer is driveninto semi-circular slots 54 and 56 in the shell and thimble as shown inFig. 6 ofthe drawing. The shell 51 also has arthreaded circular opening55 for receivingE a heat conducting core 57 inserted inside the resistorsupporting cylinder 12 and a copper soldering tip 58 which abuts againsttheend of the core .57. rllhe contact between the core 57 and thesoldering tip 58 expedites the conduction of heat from the heatingelement 10 to the soldering tip.

The soldering iron is compact and comprises relatively few parts, eachof which is removable as a unit, so that with the above describedconstruction it is an easy matter to replace any particular part orparts without discarding the entire iron. The ease and quickness withwhich the unit may be disassembled will be clearly ap arent from thefollowing description: To isassemble the soldering iron, the retainincap 40 is detached from the handle an the electrical socket 37 removedtherefrom. rlhe handle 35 with its collar 45 may be unscrewed from themember 46 ofthe tubular assembly 47 and withdrawn over the insulatingstrip 31 and connectors 32. This gives access to the screws 33 on theconnectors so that the leads 11 can be released from under the screws,thereby permitting the removal of the insulating strip 31, connectors 32and flanged sleeve 48. The metal shell 51 is yremoved by driving thewasher 53 out of the slots 54 and 56 restoring it to its originally flatcondition and Aunscrewing the shell from the thimble 51 carrying with itthe heat conducting core 57 and soldering tip 58. The heating element 10with its leads 11, supporting cylinder 12 and insulating cap '21 arepulled away from the stem insulator 23 which may be very easilyl removedfrom the tube 47. Any part can now be readily replaced and the iron canbe expeditiously reassembled ready for use. y

Although the invention as herein described and illustrated isparticularly well adapted to an electric soldering iron, it should beunderstood that the invention is adaptable to other electrically heateddevices and should be limited only by the scope of the appended claims.y C

What is claimed is:

1. In an electrical heating device, a heating means, a housing for theheating means' having a slot, an element engagin the housing andprovided with a slot, an a member interposed between the housing and theelement and engaging the slots therein for interlocking the housing andthe element.

2. ln an electrical heating device, a heating element, leads for theelement, a support for the heating element, a slotted insulating cap forthe support having a depression, and an insulatin stem provided with apassageway for gui ing the leads received from the slots in the cap andhaving an end adapted to engage the depression in the insulating cap forinterlockin the cap and stem. 3. in a heating evice, a double groovedinsulatin cylinder, a looped heating element supporte in the groove ofthe insulating cylinder, leads for the heating element, a slottedinsulating cap for guiding the leads from the heating element and havinga substantially rectangular shaped depression, a stem of refractorymaterial having a substantially rectangular end adapted to fit into thedepression m the cap for interlocking the stem and cap.

4. ln an electrical soldering iron, a heat .l

a heating element, leads for the heating element, a slotted insulatingmeans for guiding the leads into the handle, an insulating stripengaging the slot in the means for guiding the leads, and terminalslfastened to the insulating strip and extending out of the end of thehandle adapted to be inserted into anelectrical lsupply socket.

6. In a heating device, a handle, a heating unit insulated from andencasing a part to be heated, leads for the heating element, a

slotted insulating cap for guiding the leadsV from the heating unit, astem insulator having individual passagewa s for guiding the leads fromthe cap'into tlie handle, an insulating strip having a widened portion,connectors fastened thereto for engaging the leads of the heating unitand extending out of the end of the handle, a flanged sleeve having aslot engaging the widened ortion of the insulating strip forinterlocklng the stem insulator, insulating strip and handle,

- a detachable electrical supply socket for enaging the connectorprotruding .out of the andle, and a member for substantially coveringthe socket "and threaded on the end of the handle for maintaining arigid electrical contact between the supply socket and the connectors.

7.-In an electrical heating device, a handle, a heating element, leadsfor the heating element, means for guiding vthe leads into the handle,-an insulating strip housed within theha-ndle, slotted means engaging thestrip for interlocking the guiding means thereto, a

'detachable supply socket for connecting the leads to a source ofelectrical energy, and means substantially surrounding the socket formaintaining a connection between .the socket and the handle.

8.,In anfele'ctrical heating device, a handle, a heating element havingleads, a housing for the heating element having a slot, a stem forguidin element into the andle, an element encircling the stem and-havinga slot, a member interposed between the housing and the encirclingelement and engaging the slots therein for interlocking the housing andthe encircling element, terminals housed within rality of strandsextending inside a plurality the leads of the heating ofthe convolutionsof the coiled heating element and twisted with a lead of the heatingelement forincreasin the strength and-conductivity of the lea s, aslotted insulating means for guiding the reinforced leads into thehandle, an' insulating strip engaging the' slot in the -means forguiding the leads, and

terminals fastened to the insulating stri and extendinl out of the endof the hand e ,adapted to e inserted into an electrical supplysocket.

In witness whereof, we hereunto subscribeI our names this 7 dayof'December A. D., 1927.

.OWEN JAMES FAY.

HARRY TOBIAS HEIMBERGER. EMERSON PUGH.

